javax.net.debug can be used to log events at log level debug. For example, to debug all.

public class Main {	
  public static void main(String[] args) {
    System.setProperty("javax.net.debug", "all");
  }
}

Or to debug only SSL.

public class Main {	
  public static void main(String[] args) {
    System.setProperty("javax.net.debug", "ssl");
  }
}

Or to debug SSL and handshake.

public class Main {	
  public static void main(String[] args) {
    System.setProperty("javax.net.debug", "ssl:handshake");
  }
}